#region Copyright notice and license

// Copyright 2019 The gRPC Authors
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

#endregion

using System.Diagnostics.CodeAnalysis;
using Grpc.Core;
using Grpc.Shared.Server;
using Microsoft.AspNetCore.Http;
using Microsoft.Extensions.Logging;

namespace Grpc.AspNetCore.Server.Internal.CallHandlers;

internal class ClientStreamingServerCallHandler<
#if NET5_0_OR_GREATER
    [DynamicallyAccessedMembers(GrpcProtocolConstants.ServiceAccessibility)]
#endif
    TService, TRequest, TResponse> : ServerCallHandlerBase<TService, TRequest, TResponse>
    where TRequest : class
    where TResponse : class
    where TService : class
{
    private readonly ClientStreamingServerMethodInvoker<TService, TRequest, TResponse> _invoker;

    public ClientStreamingServerCallHandler(
        ClientStreamingServerMethodInvoker<TService, TRequest, TResponse> invoker,
        ILoggerFactory loggerFactory)
        : base(invoker, loggerFactory)
    {
        _invoker = invoker;
    }

    protected override async Task HandleCallAsyncCore(HttpContext httpContext, HttpContextServerCallContext serverCallContext)
    {
        // Disable certain features for client streaming methods.
        DisableMinRequestBodyDataRateAndMaxRequestBodySize(httpContext);
#if NET8_0_OR_GREATER
        DisableRequestTimeout(httpContext);
#endif

        TResponse? response;

        var streamReader = new HttpContextStreamReader<TRequest>(serverCallContext, MethodInvoker.Method.RequestMarshaller.ContextualDeserializer);
        try
        {
            response = await _invoker.Invoke(httpContext, serverCallContext, streamReader);
        }
        finally
        {
            streamReader.Complete();
        }

        if (response == null)
        {
            // This is consistent with Grpc.Core when a null value is returned
            throw new RpcException(new Status(StatusCode.Cancelled, "No message returned from method."));
        }

        // Check if deadline exceeded while method was invoked. If it has then skip trying to write
        // the response message because it will always fail.
        // Note that the call is still going so the deadline could still be exceeded after this point.
        if (serverCallContext.DeadlineManager?.IsDeadlineExceededStarted ?? false)
        {
            return;
        }

        var responseBodyWriter = httpContext.Response.BodyWriter;
        await responseBodyWriter.WriteSingleMessageAsync(response, serverCallContext, MethodInvoker.Method.ResponseMarshaller.ContextualSerializer);
    }
}
